Device for insertion into the reproductive tract and method of using same

ABSTRACT

A device for detection of fluid precursive to ovulation such as estrus in animals of the type having a tubular reproductive tract including an ovary (e.g., a cow). The device includes a mechanically operated sensing assembly including a water-soluble sensing element and formed to release in response to contact and dissolution of the element by ovulation precursive fluids to perform a function such as providing visual indication external of the animal by projection of a solid sighting member or by release of a dye. A time delay assembly (e.g., a blocking plug or timed closing of a sensing element bypass valve) is provided to prevent reproductive tract fluids from contacting the sensing element until a predetermined time after insertion of the device to avoid triggering by a preliminary fluid flow. The device is prevented from spontaneous expulsion from the animal by an anchor assembly adapted to engage and anchor the device into the reproductive tract wall. This anchor assembly serves also to stimulate the tract wall by altering the normal cross-sectional configuration. An effective anchor assembly includes a plurality of resilient spring-like strands each in a hoop configuration around a housing mounted into rings movable with respect to each other to collapse the hoops and project the anchor into a sensitive area for expulsion from the animal by peristaltic movement. The rings may be retained in a proximate position by an element which disintegrates after a predetermined time or in response to ovulation precursive flow.

United States Patent [1 1 Dickinson, III et a1.

[ DEVICE FOR INSERTION INTO THE REPRODUCTIVE TRACT AND METHOD OF USING SAME [75] Inventors: Ben Wade Oakes Dickinson, 111, San Francisco; Robert Wayne Dickinson, San Rafael, both of Calif.

[73] Assignee: Agrophysics, Inc., San Francisco,

Calif.

[22] Filed: Jan. 22, 1971 [21] Appl. N0.: 108,889

[52] US. Cl. 128/1 R, 128/2 F, 128/285, 128/343 [51] Int. Cl A61b 19/00 [58] Field of Search 128/1 R, 79, 200, 242, 128/235, 243, 244, 251, 271, 285, 341, 343, 345, 407, 408

[56] References Cited UNITED STATES PATENTS 3,192,928 7/1965 Horton 128/242 1,928,893 10/1933 Hoard 128/341 3,472,231 10/1969 Niebel et a1. 128/341 3,512,526 5/1970 Fielding 128/251 2,759,478 8/1956 Boltoch 128/341 1,271,456 7/1918 Flack 128/341 3,537,454 11/1970 Gordon 128/271 FORElGN PATENTS OR APPLICATIONS 684,876 12/1952 Great Britain 128/235 Primary Examiner-William E. Kamm Attorney, Agent, or FirmFlehr, Hohbach, Test, A1- britton & Herbert May 21, 1974 [5 7 ABSTRACT A device for detection of fluid precursive to ovulation such as estrus in animals of the type having a tubular reproductive tract including an ovary (e.g., a cow). The device includes a mechanically operated sensing assembly including a water-soluble sensing element and formed to release in response to contact and dissolution of the element by ovulation precursive fluids to perform a function such as providing visual indication external of the animal by projection of a solid sighting member or by release of a dye.

A time delay assembly (e.g., a blocking plug or timed closing of a sensing element bypass valve) is provided to prevent reproductive tract fluids from contacting the sensing element until a predetermined time after insertion of the device to avoid triggering by a preliminary fluid flow.

The device is prevented from spontaneous expulsion from the animal by an anchor assembly adapted to engage and anchor the device into the reproductive tract wall. This anchor assembly serves also to stimulate the tract wall by altering the normal cross-sectional configuration. An effective anchor assembly includes a plurality of resilient spring-like strands each in a hoop configuration around a housing mounted into rings movable with respect to each other to collapse the hoops and project the anchor into a sensitive area for expulsion from the animal by peristaltic movement. The rings may be retained in a proximate position by an element which disintegrates after a predetermined time or in response to ovulation precursive flow.

17 Claims, 26 Drawing Figures "MENTEB MY 2 1 i974 SHEET BF 9 PATENTEB HAY 2 1 I974 SHEET 7 OF 9 JIM iATENTEDm 2 1914 as 1 1; 423

sum 8 OF. 9 I

DEVICE FOR INSERTION INTO THE REPRODUCTIVE TRACT AND METHOD OF USING SAME BACKGROUND A major goal in the reproduction of animals is to accurately determine the proper timing in the reproductive cycle for either artificial or natural insemination. A similar problem exists for women to achieve or avoid pregnancy. In one approach, a number of attempts have been made to detect the period of time precursive to ovulation (e.g., the period of estrus or heat in a cow) with only limited success. Of course, the timing of estrus and of the overall reproductive cycle varies among female animals such as the cow, hogs, sheep, chickens, horses, and the like, or humans. For clarity the discussion herein will relate to the cow, which, like the human, has a reproductive tract including a uterus with a cervix opening into a vagina. It should be understood that, unless otherwise specified, the discussion is deemed to be also applicable to any animal of the type having a tubular reproductive tract including an ovary.

During the estrus period of a cow, which averages -18 hours, the animal is receptive to mating. The estrus period is marked by a significant increase in secretions of stringy, stretchable, clear, viscous, aqueous fluids (hereinafter denoted luminal fluids) which issue from the cervix into the vagina and uterus. To achieve best insemination results with the cow, the animal should be inseminated within 12 hours of peak estrus,

Presently, some common techniques for detecting estrus in cattle include the visual observation of a cows behavior and vocalization, observation of external secretions from the reproductive tract hanging from the vulva, and observation of her propensity to mount other cattle or stand to be mounted. One deficiency of such visual observation methods is that many cows may either have a short estrus or their estrus characteristics are minimally displayed, hence the opportunity for insemination is missed entirely or the insemination timing and fertility are poor. Furthermore, it is both difficult and expensive to continuously observe range animals such as range beef cows since they are generally only accessible to horseback riders who must be on the constant alert for estrus indicative characteristics which are either not readily visible from a distance or are of relatively short duration.

One attempt to render estrus detection more readily visible, as exemplified by US. Pat. No. 3,076,431, based upon the aforementioned mounting tendencies of other cattle, employs certain devices such as of a dye release type. These devices are attached to a cows back or head so that the mounting causes the dye to be released for subsequent observation.

Another attempt at estrus detection, disclosed in Mathiesen US. Pat. No. 3,397,020, utilizes a device inserted into the vaginal canal. The device includes a chamber open to the cervix with spaced-spart electrodes projecting therein to form an electrical circuit powered by a battery which would be closed by contact between the electrodes. Theoretically, estrus is detected by estrus secretions flowing into the chamber and closing the circuit for reading by a milliameter attached to the tail of the animal.

There are a number of deficiencies in the Mathiesen device which gravitate against its operability. Firstly, the device is illustrated as being placed in a portion of the vagina that stimulates a muscle of the cow to peristaltically push the device in a posterior direction and out of the animal. Furthermore, the device is shown with a smooth external surface and so has no means for anchoring into the vagina for a substantial period of time to prevent this peristaltic effect and resultant ejection. Thus, that device is not capable of long-term vaginal retention. The smooth internal surface, with no means for fluid bypass, will also cause local retention of vaginal mucus by the device with resultant irritation from the stagnation thereof and infection from organism growth therein. Another problem is that there are no means for distinguishing mucus which may be secreted by the vaginal tissue upon insertion of the device from luminal fluids secreted from the cervix during estrus. As explained hereinafter, it has been found that insertion of objects into the vagina stimulates preliminary luminal fluid flow from the posterior cervix which may or may not be indicative of ovulation and also stimulates the flow of low viscosity, non-stringy, adherent, aqueous secretions (hereinafter vaginal mucus) from the vaginal walls. These fluids would be mistaken for the full cycle luminal fluid by the Mathiesen device which is solely dependent upon electrical effects. Furthermore, since the dial of the milliameter is not visible at great distances, the indicator would not be economically feasible for use on range cattle which are spread over a great area. Finally, the device itself is subject to operational failures such as by breakage of the milliameter or by failure of the power supply.

Another approach to determining the proper timing for insemination which has been attempted is by artificial synchronization of the reproductive cycle for the purpose of achieving precise predictable timing of ovulation and hence insemination. For estrus synchronization, the present methods use implanted capsules or feed additives of drugs, the removal or stopping of which permits triggering of a rapid follicular maturation and ovulation. These are unstatisfactory because of high cost, poor synchronization and poor fertility. As well, there is major concern over tissue residues left in the controlled animal.

SUMMARY OF THE INVENTION AND OBJECTS The present invention relates to method and apparatus for detecting estrus or ovulation precursors in animals and human beings. The invention also relates to apparatus for modifying or synchronizing the reproductive cycle (estrus or menstrual cycle) of female animals so as to achieve precise, predictable ovulation.

It is an object of the present invention to provide a device and technique for the detection of estrus or ovulation precursors in animals based upon estrus indicative or ovulation precursor fluid secretions which overcomes the aforementioned deficiencies of conventional estrus detection techniques.

It is a particular object of the present invention to provide a device of the above type which is insertable for engagement and anchoring into the tubular reproductive tract which includes an ovary and which detects the flow of estrus indicative of ovulation precursor fluid secretions from their source into the tract.

It is a further object of the present invention to. provide means for retaining a device within the tubular reproductive tract for a substantial period of time.

Another object of the present invention is to provide a device of the above type capable of causing fluids to bypass the detection means for a predetermined period of time after insertion of the device so as to avoid the detection of reproductive tract fluid flow not indicative of estrus nor a precursor.

It is another object of the invention to provide a device of the above type insertable into the tubular reproductive tract which, responsive to detection of estrus indicative of ovulation precursor fluid flow, projects a visible solid object or tail or body of dye therefrom which is retained by the animal.

It is another object of the invention to provide an apparatus insertable into the tubular reproductive tract for stimulating the innervated tract wall to modify the timing or time phasing of menstrual cycle in women and the estrus cycle in other female animals.

It is a particular object to provide a device of the above cycle-modifying type for synchronizing such timing or time phasing so as to predictably control, stimulate, cause or inhibit ovulation.

Further objects and features of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings.

In accordance with certain of the above objects, a device insertable into the tubular reproductive tract of an animal is provided for synchronizing the time phasing and timing of the reproduction cycle in animals, as exemplified by mammals such as cattle, hogs, humans or horses, or non-mammals such as birds.

In accordance with one embodiment of the present invention, a device is provided including a body adapted to be inserted into the tubular reproductive tract of an animal of the type having an ovary. An anchor is carried by the body with outwardly projecting yieldable means serving to engage the tract wall to place it under sufficient pressure to alter the normal cross-sectional configuration of the tract in-a manner to both stimulate the innervated tract wall and also to prevent spontaneous expulsion of the device by the animal from the reproductive tract. The anchor assembly is constructed to supply less pressure than would cause pressure necrosis in the area of the engaged tract wall. To minimize disease and irritation, the body and yieldable means are formed to provide a path extending between the tract wall and the device for permitting flow or drainage of reproductive tract fluids in and around the device and past the engaged tract wall. Also to this end the outer periphery of the yieldable means is formed of a material which minimizes irritation of the tract wall. An anchoring assembly of the above type may be provided with auxiliary means for engaging the tract wall such as hooking means and adhesive type securing means. The yieldable means itself may include a layer of resilient foam around the body in which case the path is formed of a series of spaced longitudinal grooves in the foam periphery. The device may be provided with a collapsed position for ready insertion into the reproductive tract together with means for expanding the anchor assembly upon reaching the desired position within the tract.

A particularly effective anchor is one in which the yieldable means comprises a plurality of spaced-apart spring-like elements projecting from the body. Such spring-like elements may be formed into hoops carried by the body and projecting outwardly therefrom in an annular configuration transverse of the body. These spring-like elements may be in the form of a plurality of resilient strands mounted to extend longitudinal of the body and spaced-apart around the same. In an effective anchoring configuration, the strands outwardly project from the body in the form of a plurality of hoops in composite forming an enlarged annular portion around the body normally in the form of a rosettelike configuration. In one embodiment, the strands are mounted to two separate mounting members movable longitudinally of the body so that in a first mounting position the strands are compressed to form a plurality of hoops and are held in that position by a releasable retaining element. Upon release of that element, as after a predetermined time after insertion into the reproductive tract, the strands are caused to elongate and collapse to thereby be expelled peristaltically from the reproductive tract. The release element may operate in the above manner by being slowly soluble in reproductive tract fluids. A second embodiment of theretaining means is applicable for insertion into the vagina of an animal having a reproductive tract including a uterus opening through a cervix into the vagina. In this embodiment, the retaining means includes enclosed sensing means having a sensing element adapted to release the mounting members in response to reproductive tract fluids. A conduit projects from the sensing element through the cervix in communication with the uterus. A valving means having a sealed position responsive to the normally tight cervical muscles and an open position responsive to relaxation during the ovulation precursive period transmits the ovulation precursive fluids in the uterus to the sensing element to cause release of the mounting members. Other apparatus for stimulating the innervated reproductive tract wall may be employed for distending either the cervix of the uterus or both in the appropriate animals. However, such devices should be employed in conjunction with an anchor of the aforementioned type.

The endocrinoiogical effects of insertion of a device of the aforementioned type into an animals reproductive tract is fully described in the application entitled Artificial Method for Modifying the Reproductive Cycle in Animals (FHTA&H Docket No. 26395 filed simultaneously herewith). Briefly, insertion of the device described herein stimulates the flow of both cervical and vaginal fluids shortly after insertion. This initial fluid flow (hereinafter preliminary fluid flow) is usually not a precursor of ovulation or an indication of true estrus. However, it has been found that the animals reproductive cycle is modified by stimulation caused by engagement of the insertion device with the tract wall greater than a certain minimum time. The animal can be made to ovulate' at about 48 hours after device removal by the stimulation engendered by its removal. When the device is left in place, the preliminary fluid flow diminishes. After an appropriate period the luminal fluid flow recommences and is associated with or a precursor of ovulation. This stimulated cycle is normally of approximately one-half of the normal duration in the cow. Of course, the degree of shortening may well vary depending upon the animal.

A device of the aforementioned synchronizing type may be employed to anchor a device for, detecting a time period precursive to ovulation, such as estrus. The

device includes a mechanically operated sensing assembly including a sensing element responsive to aqueous fluid contact and an additional assembly for external indication of the fluid sensing. A channel is provided between the source of ovulation precursive fluid and the sensing element. This sensing element may be formed of a water-soluble material which is dissolved to actuate the sensing assembly. In one embodiment of the mechanically operated assembly, one member is urged by yieldable means towards one position and the sensing element is formed to prevent that member from being moved to that position.

The estrus 0r ovulation precursor detection device may include an assembly for external visual indication for proper timing or insemination of the animal. In one embodiment, the indicator assembly includes a dye container capable of releasing dye carried by the tract fluids to a point external to the animal. In another embodiment, the indicator assembly includes a readily visible mechanical element releasably mounted to the housing with a retaining line interconnecting the housing and element of a length to permit the element or entire indicator assembly in the form of an artificial tail to be carried externally of the animal for display.

It is usually desired to avoid detection of preliminary fluid flow as in those cases in which detection is employed to time artificial insemination because such preliminary fluid flow is not a precursor to ovulation. If so, a time delay assembly may be provided for preventing fluid detection by the above sensing element until a predetermined time after insertion of the device so that the preliminary fluids are blocked from reaching the sensing element. This predetermined time is usually several days because the preliminary fluid flow drops off in that period and the stimulated estrus and ovulation do not occur. In one embodiment, the time delay assembly includes a valve having a normally open position in which tract fluid bypasses the sensing element and having a closed position in which precursor or fluid indicator of ovulation or estrus is channelled through the opening to the sensing means after a predetermined time interval.

Substantial secretions of mucus not a precursor nor indicator of ovulation may falsely actuate the detection device which is responsive to aqueous fluid contact. Fluid samples are taken from the uterus because with a properly designed anchor only the posterior cervical rings open when the non-indicative mucus flows whereas with true estrus indicative mucus flow, the whole cervic opens so that the luminal fluid can then flow into the uterus. Of course this mechanism exists in nature to assure proper sperm transport or a proper fluid path for sperm passage from point of position in insemination to the uterus, oviducts and ovaries. Even with uterine fluid sampling, discrimination between viscous, stringy cervical and other water mucus, mucus may be necessary. Hence, several discrimination devices are employed such as a differential filter which permits passage of estrus or ovulation indicative fluid and prevents passage of mucus not a precursor nor indicator of ovulation. One type of such filter includes (a) a conical tapered pitch helical element disposed with the apex toward the sensing element, or (b) a tube having a peripheral outlet partially filled with discrete particles, or (c) a tube containing many slots or holes. The mucus non-indicative of estrus or ovulation freely flows around the particles to a peripheral outlet while the estrus or ovulation indicative fluid, because of its stringy nature, slowly flows on top of the particles to contact the sensing element. In (b) or (c) the nonindicative fluid flows through the interstices, holes or slots faster than the viscous estrus fluid and hence provides separation between them. These filters'serve the same purpose as the time delay, and permit only the estrus or ovulation indicative fluid flow to actuate the sensing assembly.

DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 illustrate a device according to the present invention. This device is inserted into the tubular reproductive tract, as, for example, the vaginal lumen of a cow. The device is capable of synchronizing the cows estrus cycle and includes an indicator element in both an internal and external position.

FIG. 3 is an enlarged cross-sectional view of the device of FIG. 1.

FIG. 4 is an enlarged view of the device of FIG. 3 illustrating a time delay means.

FIG. 5 is a cross-sectional view of the device of FIG. 4 taken along the line 5-5.

FIG. 6 is a cross-sectional view of the device of FIG. 5 taken along the line 6-6 with the anchor section removed.

FIG. 7 is a cross-sectional view of a portion of FIG. 3 illustrating the time delay valve means in a closed position.

FIG. 8 is a front sectional view of the device of FIG. 1 taken along the line 88 of FIG. 3 with the anchor means in an extended external shape.

FIG. 9 is an enlarged view of a portion of FIG. 3 illustrating means for removing the central portion of the housing.

FIG. 10 is a view on a plane at right angle to FIG. 9 illustrating the sensing means in a just released position.

FIG. 11 is a cross-sectional view of FIG. 10 taken along the lines 11-11.

FIG. 12 is a cross-sectional view of the device of FIG. 10 with the central portion removed.

FIGS. 13-15 illustrate the insertion device of the present invention with different types of reproductive tract anchors.

FIG. 13a is an end view of the anchor device of FIG. 13.

FIG. 16 illustrates an inserted embodiment of the above device in which the indicator means is of a dye releasing type.

FIGS. 17 and 18 are cross-sectional views illustrating differential filter devices.

FIG. 19 is a view in perspective of a multipurpose device formable into an anchor.

FIG. 20 is a side view of a stimulating reproductive tract anchor and cervical follower both based upon the device of FIG. 19.

FIG. 21 is a cross-sectional view of the anchor portion illustrated in FIG. 20.

FIG. 22 is an end view taken along the line 22-22 of the anchor portion illustrated in FIG. 20.

FIG. 23 is a cross-sectional view of a device including an anchoring device implanted into a reproductive tract and expellable in response to relaxation of the cervical muscle.

FIG. 24 is a cross-sectional end view taken along the line 24-24 of FIG. 23.

FIG. 25 is a cross-sectional side view of a uterine and cervical stimulator portion of an anchored device.

DETAILEDDESCRIPT ION OF THE PREFERRED EMBODIMENTS The device of the present invention functions to synchronize the reproductive cycle of animals in the manner described in the afore-identified application entitled Method for Synchronizing the Reproductive Cycle. As discussed therein, it has been found that the animals reproductive cycle is modified by engagement of the insertion device either for a longer period or for a briefer period than required to induce ovulation. After the preliminary fluid flow diminishes without having involved ovulation, the reproductive cycle continues and second estrus-indicative or ovulation precursor fluid flow occurs shortly before ovulation. This full cycle subsequent to insertion may be of shorter than normal duration. If desired, the device may include means for detecting the flow of estrus indicative of ovulation precursor fluid or a timed mechanism synchronized with the estrus cycle stimulated by the estrus synchronizer, and means responsive to said detection or timing for causing the emission of a semen supply into the reproductive tract as described in our application entitled Method and Apparatus for Artificial Insemination" filed simultaneously herewith Ser. No. 108,891, filed Jan. 22, 1971. Also, the device may include. such detection means which actuates external indication as described hereinafter.

Referring to FIGS. 1 and 2 illustrating a cow as an example, a device is inserted into the tubular reproductive tract including an ovary such as the vaginal lumen of the cow, with the front portion adjacent to the cervix from which. estrus secretions flow posteriorly when the cow comes into heat. Along with synchronizing the cow's reproductive cycle, the illustrated device functions to detect the secretions within the housing and to provide an external indication in response to the same. The housing is held in a generally fixed position by means of an anchor.

In order to detect estrus in a cow, a device of the type illustrated in FIGS. 3-7 is provided which includes a mechanically operated sensing assembly responsive to estrus indicative fluid, a channel between the sensing element and source of estrus fluid and means for anchoring the device within the reproductive tract. The particular embodiment of the device illustrated in FIGS. 3-7 includes an elongate housing 20 of a generally cylindrical configuration suitably forrned of a rear section 20a slideably and removably received within a portion of the concentric forward section 20b. Spaced-apart fluid outlet ports 23 are positioned about the periphery of section 20a. This enables gravitational fluid removal from the housing regardless of radial orientation. As will be apparent, the entire device is constructed to accommodate radial movement without affecting its functional characteristics. Annular front wall 21 of section 20b is blunted at the edges to abutt against the vaginal wall adjacent to the cervix in a generally fluid sealing manner and defines an inlet port 22. Valve chamber 24 is disposed within section 20b and provides fluid communication between port 22 and the remainder of the fluid passage through the housing. Chamber 24 is provided with four spaced-apart circular bypass ports 26 to permit the flow of cervical secretions through port 22 and out of ports 26 under the force of gravity. Section 20a is removable along with the core of the housing so that after external indication of estrus (or other ovulation precursive fluid) the core of the device may be replaced with a semen dispenser for urging semen through port 22 into the cervix. For this purpose as shown in FIG. 11, two elongate slots are provided at opposite sides of section 20b. As best illustrated in FIGS. 9 and 11, flexible retainer strips 28 ride within each slot so that one end is affixed to section 20a at the rear end of the slot and the other end is free to pivot and includes a retaining shoulder 280 which mates with an accommodating recess in housing section 20b. Shoulder 28a is of a sufficiently resilient material to prevent disengagement of sections 20a and 20b after insertion into the recess. These sections are manually releasable by pressing inwardly against retainer elements 28 and sliding section 20b out of section 20a. Raised portions 28b serve to render elements 28 more accessible to facilitate this manual operation.

, Referring to FIG. 12, the shell of section 20b is illustrated in an anchored position with the internal working parts removed along with section 20a in the above discussed manner. Open section 20b is then adapted to form a housing for a device such as the inseminator of the application filed herewith entitled Automatic Artificial Insemination Apparatus and Method" Ser. No. 108,891, filed Jan. 22, 1971.

In order to anchor housing 20 within the animals reproductive tract to preent spontaneous expulsion of the same by the animal and also to alter the normal crosssectional area of the tract wall to stimulate the same, an anchor assembly 30 is mounted around housing 20. A number of embodiments of such anchors are illustrated hereinafter of the type with radially projecting yieldable means being formed to provide a path extending between the tract wall and the device to minimize infection. Referring to FIGS. l-l2, assembly 30 may be comprised of a plurality of resilient strands 32 each of which is slidably received within slots of radially spaced raised knobs 33a and 33b arranged in adjacent circumferential rows about section 20b to form the strands into a series of loops forming a composite rosette-like annular pattern. As illustrated in FIGS. 7 and 8, the ends of individual strands 32 are retained within slots of knobs 33a and 33b which are radially unaligned by the span between adjacent radial slots in the circumferential rows to cause a slight spiral shape to the individual strand which serves to form the hoops into a more compatible configuration. The material of strands 32 should be yieldable for ready travel through the reproductive tract so that it may project into folds within the vaginal lumen in a slightly compressed yieldable manner with sufficient resiliency .to engage the vaginal wall in a generally retaining manner to avoid spontaneous expulsion. Also, the anchor assembly 30 is formed with a path provided through the hoop openings to minimize infection by retention and stagnation of mucus within the device in contact with the vaginal tissue. This requirement is equally applicable to other portions of the device which contact the vaginal wall. Nylon is a particularly effective anchor material for both minimizing irritation and for proper resiliency.

To cause synchronization as described in copending application Ser. No. 108,922, filed Jan. 22, 1971, it is important that the anchor stimulate the innervated tissue of the tubular reproductive tract or vaginal lumen of an animal such as the cow by the application of suffi- 9 cient pressure at the anchor periphery to alter the cross-sectional configuration of the tract wall. The pressure exerted by the anchor should be insufficient to cause pressure necrosis in the area of the engaged tractwall. A device of the aforementioned type having an outer diameter in an expanded state and of fairly resilient material such as 7.5 inch outside overall diameter nylon loops is particularly effective.

An indicator assembly 34 is releasably mounted to housing and includes a hollow spherical indicator element 36 yieldably mounted to the housing by means of spring member 38. Although element 34 may be of any shape, sharp edges should be avoided to prevent irritation of the vaginal wall. Indicator element 36, suitably of a non-irritating plastic material, includes a slotted portion 36a serving to provide an entrance point for the end of spring member 38 for mounting by rotating the sphere so that the spring projects into the same in a spiral manner. The other end of spring member 38 is urged against a projecting portion of housing section 20a but is not affixed thereto. A protective sheath 40, suitably of a non-irritating flexible material such as nylon, is provided to cover the entire exposed area of spring member 38 and affixed at each end to the same so as to protect the tract wall from irritation by expansion of the spring and movement of the same through the tubular reproductive tract to the exterior. The sheath also serves to prevent the tract all from clamping the spring during this passage under the influence of the sphincter-like muscular contractions at the inward boundary of the reproductive tract vestibule as explained hereinafter. The location of the indicator assembly is immediately anterior to that inward boundary to avoid spontaneous expulsion by peristaltic contractions of the animal. Sheath 40 is of sufficient length to expand upon release of spring member 38 and forms a series of small irregular folds upon compression of the spring. Sheath 40 and spring member 38 and indicator element 36 move as a unit away from the housing to project from the animal upon release of the internal retaining device as explained hereinafter. Thus the expanded external sheath provides additional visibility for the indicator element.

Mechanically operated estrus fluid sensing assembly 42 retains indicator element 36 adjacent to housing 20 in a fixed position and, upon actuation, permits spring member 38 to move element 36 away from the housing for eventual peristaltic movement out the tract to the exterior as explained hereinafter. Sensing assembly 42 includes retaining body 44 formed of portions 44a and 44b in the outer configuration of mating cylinder halves which include facing sloped surfaces for clearance during actuation of the sensing means as illustrated in FIG. 10. The inner walls of body 44 define a chamber 45 for seating truncated conical shoulder portion 480 of member 48. The other end of member projects into and is affixed within element 36 as illustrated in FIG. 3. To accomplish this, element 36 may be split into hemispheres and formed about member 48. Indicator element 34 is retained adjacent to the housing by member 48. A cross pin 46 is journaled in housing section 20b and passes through portions 44a and 44b to provide linkage with the housing. Portions 44a and 44b are retained in abutting position by sensing element 50 of an adhesive type extending around the entire circumference of the same. Sensing element 50 is formed of a material which has a relatively high tensile strength and which is soluble in water or in a solution (e.g., estrus) with a high aqueous concentration. Although other water soluble materials may be employed, polymers of the calendered polyethylene type such as sold under the trade name of Polyox"'by Union Carbide Corp. (with a high tensile strength and high solubility in the water of the reproductive tract fluid but not in nonaqueous solutions) have been found to be particularly effective. Dissolution of sensing element 50 triggers the rearward movement of member 48 and thus of indicator element 36 under the urging of spring member 38.

The water soluble material of sensing element 50 such as polyethylene oxide (Polyox) may be irradiated with electrons or gamma rays to change its water solubility properties or coated with a suitable material such as napthalene or parodichlorobenzene which sublime in a reproducibly timed action at the fixed animal vaginal temperature so that the polyox is not exposed to water until a predetermined time delay has transpired. The water soluble material-should also be insoluble in acceptable non-aqueous bacteriostats or disinfectants such as sold under the name Furascin. Polyox has this desirable property.

Means are provided for retaining the released indicator assembly 34 in a loose carried position externally by the animal. Such means include a retaining plug 52 received within the outer end of housing section 20a and affixed thereto as by adhesive. A flexible retaining line is affixed at the end to plug 52 as by extension therethrough with an enlarged anchor portion and at the other end to member 48. Line 54 is of sufficient length to permit element 34 to hang from the animal upon actuation of sensing assembly 42 as illustrated in FIG. 2.

A time delay means is provided to prevent fluid detection by the sensing element until a predetermined time after insertion of the present device into the animals reproductive tract. In one embodiment of a time delay means, a valve assembly 56 has a normally open position to allow fluids to bypass the sensing element through ports 26 and a closed position in which the same ports are sealed so that the reproductive tract fluid flowing through inlet port 22 is directed through housing 20 for contact with sensing element 50. Valve assembly 56 includes piston 58 in the form of an annular sleeve slideably received within housing 20 and having an open and closed position. The wall of piston 58 is thicker at its forward end to provide a larger seating area and, thus, a correspondingly better liquid seal between the piston and the inner surface of wall 21. In an open position, piston 58 is in the position shown in FIG. 3 and is urged to the left by engagement with compressed spring 60 which is backed by cross pin 46. Piston 58 is prevented from movement into a closed position by latch mechanism 62 which includes a U-shaped retaining element 64 pivotally mounted at one end to cross pin 46 as by engagement with hooking portions 640 and positioned at the other or crossbar end 64b within recesses of latch member 66. The latch member is pivotally mounted on bar 68 which is journaled into the sidewalls of piston 58 as shown in FIG. 4 so that the latch is carried by the piston during linear movement.

Referring to FIG. 5, a motion creating mechanism 69 is provided within the housing for actuating latch mechanism 62 and thereby permitting piston 58 to block bypass ports 26 and may be of the types described in our copending application entitled Method and Apparatus for Creating Motion filed simultaneously herewith Ser. No. 108,892, filed Jan. 22, 197 l now abandoned. In the embodiment illustrated herein, mechanism 69 includes a container 70 separated into a first fluid supply compartment 71 and a second or expandable material compartment 72 by a permeable partition 73. Compartment 72 is defined by a flexible membrane 74 which is carried between a casing 75 and annular sealing plug 76 which cooperate to form an external fluid seal for membrane 74. To form an effective seal, plug 76 is formed of resilient material so that it is urged outwardlyand is of a shape to provide separate mating surfaces with the membrane. Compartment 71 is defined in part by cup 77 with an inwardly projecting rim for sealing engagement with a portion of plug 76. The partition 73 is mounted in a stretched configuration between plug 76 and a resilient adaptor plug 78 so that the two plugs are compressed to provide a fluid seal. The partition is formed of a material such as cellophane which is semipermeable to the fluid (e.g., water) in compartment 72. Plug 78 includes an annular opening for a wick 79 which contacts'the partition for ready absorption of fluid in compartment 71. The rate of fluid diffusion through the partition may be controlled by varying the size of the opening in the adaptor plug to vary the corresponding exposed surface area of the partition.

Casing 75 includes a clearance slot 80 for permitting latch member 66 to pivot into a piston releasing position and also includes a recess 81 to allow bar 68 and latch member 66 to slide with piston 58 to a closed valve position. Casing 75 is retained in axial alignment centrally of housing 20 by means of three equidistant radial pins 82, carried by the casing and projecting through accommodating clearance slots 58a of the piston to abutt at the outer ends against the inner wall of housing 20. These slots allow the piston to slide into a closing positon without movement of casing 75 and provide a linkage for the removal of piston 58 upon removal of housing section 20b as described hereinafter.

An expandable material is placed in compartment 72 capable of expansion upon contact with fluid supplied to compartment 72 which is absorbed by wick 79 and diffused through partition 73. In one system, the fluid is water and the expandable material may be either polyethylene glycol, sold under the trade name of Carbowax or the albumin derivative, peptone. With either material the water slowly diffuses through partition 73 to cause the material in compartment 72 to expand by creating a high molecular weight polymer to thereby expand membrane 74 and force latch 66 to pivot in radial outward direction as shown in phantom in FIG. 5. Thereafter, piston 58 is urged forward to block bypass ports 26 and to cause fluids to pass through the housingto contact sensing element 50.

The foregoing valve assembly provides a means for chanelling fluids through the housing to contact the sensing element 50 only after a predetermined time delay. In this manner, the preliminary luminal fluid bypasses the sensing means while the second fluid flow is directed to the same. ltis apparent that this time delay is dependent upon the amount of time it takes for the fluid passing through partition 73 to expand membrane 74 to a sufiicient extent before pivotal movement of latch member 66 away from member 64 for closing of piston 58. The timing may be controlled by varying the partition material or the exposed surface area to control the diffusion rate and by varying the type and quantity of expandable material.

Another time delay means (not shown) includes a blocking plug disposed in said channel for blockage thereof either of a slowly vaporizable or sublimable material at the temperature of the reproductive tract or of one slowly soluble in reproductive tract fluid. In either type of plug, the material disappears sufficiently for fluid bypass in a time period longer than that which elapsed between insertion of the device and completion of the preliminary fluid flow. Such materials of the slightlY soluble type include polyethylene oxides (Polyox) cross-linked (e.g., by irradiation). Sublimable materials include paradichlorobenzene and napthalene.

A device of the foregoing type is employed for the detection of estrus by insertion into the animal s tubular reproductive tract as exemplified by a cow for the present description. It should be understood that the device may also be used on other animals of this type such as horses, chickens, sheep and hogs. In the cow, as an example, the device is inserted so that the front part of housing 20 abutts against the vaginal wall in fluid sealing engagement with inlet port 22 adjacent to the cervix. The tubular reproductive tract is easily distendable with little or no discomfort or feeling in the animal. It has been found that foreign objects placed in the vestibule cause the animal to strain, to push her cervix posteriorly and to create a peristaltic reaction to force the object posteriorly out of the vulva. These ejection phenomena do not occur with vaginal placement in the cow. The vaginal wall, proximal to the cervix and anterior to the highly sensitive vestibule of the vagina, is also comparatively insensitive to pain as would be engendered by fish hook placement, etc. In a typical cow, the axial distance of the sensitive vestibule extends about 4 inches inward from the vulva to the end of the region of easily induced peristaltic muscular activity. The insensitive vaginal cavity may vary from about 4-6 inches in the smallest cattle such as a beef heifer to about 12 to 14 inches in a milk cow which has had several calves and has a very flaccid vagina. It is this insensitive region in which the device should be implanted in order to avoid promoting an ejection activity. It has been determined from vaginal castings of many cows vaginas in vivo with and without devices in place, that this insensitive vaginal region is normally flat but can be distended to a diameter of 8 inches or more by an anchor assembly. Observation of the animals with the distended vagina indicates that there is no apparent discomfort to the animal. The limiting factor for device placement is the distance between the pin bones on either side of the animals vulva which range from 2 inches in a heifer in the cow, to 3% inches in a full grown cow which has had several calves. Afully expanded anchor assembly as in FIG. 8 may be inserted into the animal and compressed as shown in FIG. 7. The strands 32 tend to extend against the vaginal wall and particularly expand against the posterior vaginal sphincter muscle so as to hold the device in place. We have found that having a small diameter (1 inch or less) rod, not shown, residing in this vaginal vestibule to the posterior of the sphincter muscle tends to stabilize the device against disorientation within the vagina. This rod is desirable because each time the cow defecates, she moves her cervix several inches posteriorly and tends to shorten her vaginal barrel by several inches with a consequent tendency to disorient the device.

Valve means 56 operates by the release of latch mechanism 62 which enables compressed spring 60 to urge piston 58 forward to a closed position as shown in FIG. 7. Latch mechanism 62 is actuated by the timedelay expansion of membrane 74 forcing latch member 66 in a radial outward direction and thus releasing element 64 which retains piston 58 in its first open position. The expansion of membrane 74 is by filling compartment 71 with water, allowing wick 79 to absorb a portion of the water for contact with partition 73, and diffusing the water across the membrane into compartment 74 wherein a material expands on contact with the water and urges correspondingly expanded membrane 74 against latch mechanism 62 to force the same in a radial outward direction. After release of the latch, piston moves to a closed position in which bypass ports 26 are blocked. Latch member 66, anchored by cross bar 68 in the side-wall of piston 58, slides through recess 81 of casing 75 along with the piston.

After closure of bypass ports 26 by piston 58, the estrus indicative or ovulation precursor fluid emitting from its source is directed through the open passageway of housing to contact sensing element 50 and to thereby dissolve the same. After dissolution, retaining members 440 and 44b pivot apart and indicator element 36 is urged away from the housing under the compression of spring member. Element 36 is retained in loose engagement with housing 20 by means of flexible line 54 anchored in retaining plug 52. Spring member 38 may be under sufficient compression to urge indicator element 36 through the entire length to exit from tubular reproductive tract. However, it has been found, in the cow as an example, that it is only necessary to project the indicator element into the aforementioned sensitive vestibule adjacent to the vulva of the cow. Thereafter, the indicator element is peristaltically moved along the tract lumen wall and out of the ani mal. Line 54 should be of sufficient length so that the indicator element and appendant sheath covered spring member 38 hang from the animal for ready visual detection. Placement of the untriggered device so that a portion normally projects through the posterior vaginal sphincter muscle also assures that the trigger tail or indicator is properly oriented for passage out the vestibule and vulva for display and indication.

The inner core of the device is removable leaving only in the case of a cow as for example the housing section 20b in a position retained in the tract by anchor assembly 30 as shown in FIG. 12. One purpose for this is to provide a convenient retaining housing for insertion of a slow release semen supply with an outlet adjacent the source of the estrus indicative of ovulation precursor fluid. Suitable semen supply devices are illustrated in our copending application filed simultaneously herewith, entitled Artificial Insemination Apparatus and Method Ser. No.'108,89l, filed Jan. 22, 1971. To remove this core, the raised portion 28b of retainer element 28 is pressed inwardly to. disengage shoulder 280 from its accommodating recess in housing section 20b. Thereafter, section 200 is free to be slideably moved away from section 20a which in turn is connected to all remaining core elements to pull the same out of section 20a. Section 20b is connected by cross pin 46 and through element 64 to casing 75 so that the tract secretions out the exit of the tract of the animal latter is withdrawn by sliding section 20a out of section 20b. During removal, when pins 82 of casing reach the rearward end of slots 58a, they engage piston 58 and latch member 66 journaled therein by bar 68 for withdrawal of the entire core of the housing. v

FIG. 16 illustrates an embodiment of the present invention in which a dye is released as an indicator in place of the solid indicator portions of assembly 34 in the foregoing device with similar operation of the device prior to indication. A dye container 102 is disposed within housing 20 and includes a front wall 103 formed of a material such as thin elastomeric membrane which is penetrable by a pointed object. The dye is of a type such as Rhodamine B, which is visible at a great distance.

In this instance, sensing assembly 42 actuates a penetration assembly 104 which includes a generally cylindrical ram 106 having a conical pointed end portion 106a, an enlarged cylindrical portion 106b, a truncated conical retaining shoulder portion 106c and a tail portion 106d. Ram 106 is slideably received in bearing 108 supported by radiating spokes 110 journaled into the housing section 20b so that the ram is in axial alignment with the housing. Spokes 110 provide a passageway for fluid to flow out of the housing through outlet ports 23. Ram 106 is urged toward a position to pierce wall 103. compressed by helical. spring 112 disposed within a recess in body 44. The ram is retained under compression by portion 106c being pressed-against an accommodating recessin body 44. To further promote axial alignment of ram 106 after actuation, portion 106 projects into the central core of springll2. Portion 106c serves to stop the forward movement of the released ram when it reaches bearing 108. Ports 23 of housing section 20b provide the dual function of allowing estrus indicative or ovulation precursor fluids and the released dye to flow out of the housing, through the tract, and out the exit. Housing section 20b is releasable from section 20a in'the aforedescribed manner.

In operation of the device of FIG. 16, estrus indicative or ovulation precursor fluid contacts and thereby dissolves sensing element 50' so members 44a and 44b pivot apart to release portion 106c as in the foregoing device. Thereafter, spring 112 urges ram106 forward until portion 106a pierces front wall 103 of the dye container to release the dye which flows out of the housing through ports 23 and passes along with the for ready visual detection.

For use in place of the aforementioned time delay mechanism to avoid triggering of sensing element 50 by preliminary fluid secretions, differential filter systemsare provided of the type illustrated in FIGS. 17 and 18. These differential filters serve to selectively channel ovulation precursive fluids, which are stringy and stretchy in comparison to the preliminary fluids, to another embodiment of a sensing assembly 42, Sensing assembly 42 may be'employed in place of the aforediscussed more complex sensing assembly 42. For example, assembly 42 would be particularly effective for use in conjunction with the aforedescribed disintegrable blocking plug .time delay mechanism. Assembly 42 includes a housing 86 in which is journaled a cross bar 87 which carries element 88. Sensing element 50' assumes the form of a ring in this instance which passes through a bore in member 88 and similar bore in member 89 to interconnect the two members. Element 50 is may be formed of the same type of material as element 50'. Member 89 may be associated with an indicator assembly'similar to the ones aforedescribed which is biased with respect to element 89 so that release of that element causes movement away therefrom for actuation of the indicator assembly.

Referring to the differential filter assembly in FIG. 17, a frame 90 including a flexible nose 91 adapted to mate with the opening of the cervix and two cupshaped members 92 and 93 which carry the largediameter end of helical elements 94 and 96 respectively. These last named each have a conical helical configuration. The small end of element 94 mates with an-opening in member 93 while the same end of element 96 mates with a projecting lip of housing 86. Retaining bars 97 are provided to maintain helical elements 94 and 96 in the desired configuration. Cupshaped member 92 includes raised mounting knobs 98 for retaining a series of resilient strands 99 as an an- ..choring assembly similar to the one illustratedin FIG.

flows from the cervix through nose 9! into helical ele- 1 meat 94. Due to its water nature most of that fluid drains through the spaces between adjacent twins of the helix and that portion which passes element 94 drains out the spaces in element 96 so that no substantial quantity of fluid contacts sensing element 50. On the other hand, the fluid precursive of ovulation, being of a stringy and stretchy nature, tends to build up with elements 94 and 96 and form a cohesive bridge over which the ovulation-precur'sive fluid flows to dissolve sensing element 50to thereby release the indicator as sembly. It should be understood that the number of helical elements which are employed inseries is dependent upon the effectiveness of each individual'element.

Another embodiment of a differential filter, illustrated in FIG. 18 includes a plurality of layered filtering balls, 101 carried within and partially filling an open housing 43 which includes a nose mating with'the cervical opening and a rear portion formed integral with housing 86'. As in the embodiment of FIG. 18, knobs 98' are provided on housing 83 for retaining a series of properties of the ball layer are such that the spaces in Y the layer are plugged by-the ovulation precursive fluids to thereby form a bridge, across the layer for the same fluid to contact and dissolve sensing element 50' of sensing assembly 42. I

Referring to F168. 13 and 13a, another embodiment of an anchor assembly is illustrated which includes a resilient flexible foam layer 1 10 which may be carried by and affixed to the outer surface of a body insertable into the reproductive tract such as housing 20. A series of spaced-apart channels 111, best illustrated in FIG. 13a, are formed in the outer periphery of the foam layer to facilitate the passage of reproductive tract fluids thereby. These channels are in the'form of grooves or teeth with a narrower spacing at the outer than the inner portion so that fluids may pass through the nar- 16 row portion into the large channel but the tract wall is prevented from substantial ingrowth to block the channels. If foam layer 111 has sufficient porosity under compression in situ for the passage of fluids, then channels 111 are unnecessary. It is preferred that the foam be formed of a resilient material such as foamed polyurethane and that the layer be of sufficient thickness that it presses against the tract wall under sufiicientcompression for frictional engagement therewith and to alter the normal cross-sectional area of the vagina. This foam may be encapsulated with a suitable covering such as a nylon film to reduce irritation to the vaginal wall or retention of mucus with possible infection from organisms growing therein.

Referring to FIG. 14, another embodiment of an anchor assembly 30'is shown in which a series of spacedapart plates 112 are mounted as with spring-like supporting rods 113 to housing 20. A layer 114 of tissue adhesive material is coated upon plates 113 which is capable of forming an adhesive bond with 'the tract wall. Suitable materials of this contact cement type include many homologues of the cyanoacrylate cements. The reproductive tract fluids are able .to flow from the tract wall past plates 112 through the spacing therebetween. v

Referring to FIG. 15, still a further embodiment of an anchor assembly 30 is mounted on plates 112 similar to plates 112 supported by' spring-like supporting rods 113 similar to rods 113 and includes hooking means comprising J-shaped fish hooks 114' mounted to the plates as with bolts 116 with the hooking portion 117 projecting from the plate facing therear of the device.

Hooks 114'- are provided with resilient projecting protective rods 118 also'mounted to bolts 116 and extending therefrom to a position adjacent to the point of portion 117. As shown in FIG. 16, rods 118 prevent the hook from being implanted in the vaginal wall upon in-.

'sertion of the device but will be urged toward the .housing for hooking into the tract'wall' to inhibit movement in the'rever'se direction. 1 l v v The various anchor embodiments described herein may be formed to be partially collapsible, if desired; to

a sufficiently small size to be readily inserted into the Referring to FIG. ,19-22, an anchor assembly of adjustable size and shape is illustrated independent from the sensing and indicating assemblies for the purpose of stimulating the innervated reproductive tract wall by altering the normal cross sectional area as described above. The basic unit 119 in this assembly,'as shown in FIG. 19, includes a plurality of spaced-apart longitudinally extending resilient flexible strands 120 formed of a a material suchas nylon, which are mountedat opposite ends in a pair of mounting rings 121 and 122. Ring 7 121 may be provided with a recessed collar 124,

adapted to be slideably received within a mating ring. FIGS. 20-23 illustrate the use of unit 119as an anchor assembly in which rings 12! and 122 are slideably carried on a cylindrical central core 124. Ring 122 is preferably movable longitudinally of core 124'toward ring 121 into the illustrated position so that the strands 119 project outwardly from core 124 into a series of hoops 1 19 in composite forming an enlarged annular portion. The illustrated rosette-like pattern is desirable because of its ability to yield in a flexible uniform manner after insertion as shown in FIG. 23. The formation of the rosette configuration in a conforming manner to avoid interference among the individual hoops 119 as illustrated in FIG. 22, is assisted by rotation of mounting rings 121 and 122 relative to each other prior to affixation to core 124. It is further apparent that the extent of outward projection of hoops 119 is governed by the distance set between rings 121 and 122.

Retaining means for rings 121 and 122 may include a plurality of strips 126 as of adhesive interconnecting the rings and fitting through slots therethrough with the strips being tied at their extremities to the rings. Another means for retaining the rings is to form the rings themselves of a stretchable material which presses against core 124 after being slideably mounted thereon. Or, the retaining means may comprise a pin, not shown, forced through the rings to be urged against core 124. Any of these retaining means may be formed to release a predetermined time after insertion into the reproductive tract such as after a sufficient period of time has passed to allow stimulation of the tract wall. One means to cause such release is to form the retaining means of the same type of material as used in the aforedescribed disintegrable plug (e.g., slightly soluble irradiant polyethylene oxide or a slowly sublimable material such as paradichlorobenzene). Upon disintegration of the retaining means, the rearward ring 122 and attached strands 119 slide into the sensitive vestibule of the reproductive tract responsive to urging by the resiliency of the springs in a hoop configuration. With the anchor device projecting into this sensitive area, the animal begins to peristaltically move the device toward the vulva. Since the anchor is in a substantially collapsed position, this peristaltic movement will continue until the entire anchor assembly has been spontaneously expelled from the animal.

Referring to FIG. 23, an anchoring device is illustrated utilizing basic unit 119 with movable mounting members and which is capable of self-actuating anchor collapse and consequent spontaneous expulsion of the device in response to the flow of ovulation precursive fluid. This device may be used for insertion into the vagina of a cow or other animal having a reproductive tract includinga uterus opening through a cervix into the vagina. As explained hereinafter, the device utilizes a discovery by applicants that the posterior s, denoted 130, of the cows cervix relaxes to permit fluid flow thereby only during the flow of fluids precursive to ovulation or estrus in the cow. In general, the illustrated device includes a cervical anchor assembly, an outwardly projecting vaginal assembly, and releasable retaining means for maintaining the latter assembly in an outwardly projecting position. In the illustrated embodiment, the retaining means includes a tubular housing 131 sealed at the posterior end by plug 132. Tube 133 is disposed concentrically within housing 131 supported on one end by annular retaining wall 134 and at the other end by annular sealing wall 136 through which the tube projects to form a mounting tip for flexible tubing 137 which, in turn, is of sufficient length to project through the cervix into the uterus as illustrated in FIG. 23. A sensing chamber 138 is defined by plug 132, wall 134, and that portion of housing 131 extending therebetween. An annular sensing element 139 is disposed within chamber 138 and is formed of a material soluble in reproductive fluids (e.g., polyethylene oxide) as previously discussed. Retaining plugs 140 are mounted within spaced-apart openings and are supported by sensing element 139.

The vaginal anchor assembly includes a plurality of resilient strands formed into a number of resilient loops in a configuration before insertion of the device as illustrated in FIGS. 20 and 22 and after the same insertion as illustrated in FIG. 23. It is apparent that strands 141 form an anteriorly directed umbrella-likeshape of the initial rosette-like pattern as a result of a partial collapse during insertion into the vagina. It is further noted that the strands penetrate into folds of the vaginal wall in intermeshing fashion and are urged against the anterior side of the vaginal sphincter-like muscle under sufficient pressure for firm retention of the device in that position. The anterior end of strands 141 are fixedly secured to anterior mounting ring 135 which, in turn, is carried by housing 131 as by forming the ring of a resilient material and sliding the same over the housing to form a tight fit. A posterior mounting ring 143 is slideably carried by housing 131 and is maintained in the illustrated position by abuttment against retaining plugs 140.

A cervical anchor assembly includes a clamping ring 144 which is of a size large enough to be slideable over the projecting annulus of the cervix and small enough to be retained thereon. Clamping ring 144 is connected to housing 131 in a flexible manner by means of a series of spaced-apart elongated strands 146 fixedly secured at one end to the clamping ring and at the other end to mounting ring 147 which, in turn, is fixedly secured to and carried by housing 131. It is apparent that the cervical anchor assembly incorporates a shortened version of basic unit 146 previously discussed. The retention of the posterior portion of tubing 137 within the cervix may be assisted by a series of spokes projecting inwardly from clamping ring 144 and urged against the tubing. Strands 144, under compression, urge the opposite ends of the device apart to axially stretch the vagina to thereby stimulate the same.

In one illustration of the device illustrated in FIGS. 23 and 24, the device is pushed into the vaginal cavity with tubing 137 being positioned within the cervix as illustrated, with clamping ring 144 being affixed about a projecting lip of the cervix as illustrated, and with the vaginal anchor forming an umbrella-like configuration upon sliding through the vagina with the periphery of the umbrella abutting against the anterior side of the aforementioned sphincter-like vaginal muscle. This latter abuttment serves to provide the anchor with a backing for a secure position. During preliminary and other reproductive tract fluid flow, cervical muscle remains in a contracted position to provide a valve which seals conduit 137 from any substantial fluid flow therethrough. During the estrus period of the cow, muscle 130 relaxes and fluid flows from the cervix into the uterus to combine with the uterine fluids which flow through tubing 137 in the new open-valve position, proceeds through tube 133 and into sensing chamber 138. When a sufficient quantity of fluid fills chamber 138, water soluble sensing element 139 will dissolve to a sufficient extent to weaken the support that the element provides for retaining plugs 140. The spring-like compression of strands 141 in a hoop-like configuration will then urge slideable mounting ring 143 posteriorly to force the retaining plugs into chamber 138 and to thereafter project well into the sensitive vestibule on the posterior side of the vaginal sphincter-like muscle. As previously discussed with respect to the embodiment of FIGS. 20-22, this rearward motion causes the collapse of a substantial portion of the outer projection of the anchor assembly to release the securing effect of the same. Thereafter, the animals natural peristaltic muscular movement will urge the posterior end of the anchor assembly, now projecting into the sensitive vaginal vestibule, along with the remainder of the device for spontaneous expulsion by the animal from the vagma.

Referring to FIG. 25, a combination of a cervical and uterine stimulator is illustrated which is used in conjunction with the vaginal anchor assembly illustrated in FIG. 23. The cervical stimulator is illustrated in the form of a helical element 149 mounted at one generally straight end in a retaining sleeve 150 which is, in turn, retained within a cervical ring 151 by means of spokes 152 which permit bypass of the spokes by fluids emitting from the cervix. The other end of element 149 is attached to the uterine stimulator illustrated as an enlarged helical element 153 by means of a generally straight connecting link 154 which does not disturb the normally tight cervical muscle 130 discussed hereinbefore. The anchoring for thiscombination uterine and cervical stimulator is generally the same as that illustrated in FIG. 23 with the exception that cervical ring 151 is not urged tightly against the projecting cervical lip as is clamping ring 144. This is to avoid possible damage to the cervix by simultaneous exterior and interior pressure. It is noted that the uterine and cervical stimulators distend the uterus and cervix, respectively, to provide the desired amount of stimulation. It should be further noted that normally the afore-described anchors provide sufficient stimulation to alter the reproductive cycle of the animal as previously discussed. Thus, the stimulators illustrated in FIG. 25 are only required in those exceptional cases in which a massive amount of stimulation is either required for such effects or is desired for some other purpose.

Although that portion foregoing description relating v to devices for the detection of ovulation precursive fluids functions to trigger a visible indicator, it should be understood that the device may also be employed for other purposes such as to actuate the direct release of an accompanying supply of semen inserted in the animals tubular reproductive tract at the same time. In that instance, the device is employed solely for proper timing of artificial insemination and no visual indicator is necessary. Devices of this type are disclosed in our application, filed simultaneously herewith, entitled Automatic Artificial Insemination Apparatus and Method Ser. No. 108,891, filed Jan. 22, 1971.

It should be further understood that a number of modifications in the foregoing device may be made without departing from the scope of the present invention. For example, other mechanical sensing devices which are actuated in response to contact with ovulation precursive fluids may be employed. Furthermore, indicators other than the disclosed release of the dye and projecting indicator element may be employed so long as they are responsive to actuation of the sensing assembly and are visible at a substantial distance from the animal.

The anchoring device may also be modified in accordance with the present invention to prevent spontaneous expulsion of the device, itself, or of the detection device, if used therewith. Furthermore, other devices which perform the additional function of the anchoring assembly of modifying the reproductive cycle by altering the normal cross-sectional area of the reproductive tract to stimulate the small fall within the scope of the present invention.

We claim:

1. In a device for insertion into the vagina of an animal of the type having a vagina terminating at the posterior end in a normally closed vulva and at the anterior end of the cervix, said vagina being defined by a foldcontaining vaginalwall with a defined annular sphincter muscle intermediate the cervix and the vulva, said device comprising mounting means with an annular surface and spaced-apart yieldable means carried by the mounting means and projecting axially of the annular surface and being disposed circumferentially about an axis generally coincident with the axis of the annular surface, said spaced-apart yieldable means being capable of being compressed to a size so that the device can be readily inserted through the vulva into the vagina, said device being of a length so that it can be disposed between the cervix and the sphincter muscle, said spaced-apart yieldable means serving to place pressure upon the vaginal wall to distend the same from its normal cross-sectional configuration, said spaced-apart yieldable means defining a plurality of spaced channels adapted to permit vaginal fluids to bypass the same, said device being adapted to be completely disposed within the vagina to permit the vulva to assume its normally closed position.

2. A device as in claim 1 in which said spaced-apart yieldable means are movable between collapsed andexpanded positions, said yieldable means in a collapsed position being readily insertable into the animals vagina and in an expanded position engaging the vaginal wall.

3. A device as in claim 1 in which said yieldable means is deformable at the ambient temperature of the animals vagina to partially collapse after insertion of the device.

4. A device as in claim 1 together with a body and in which said mounting means comprises two separate mounting members carried by the body and engaging said yieldable means at points spaced longitudinally of the body and assuming first positions.

5. A device as in claim 1 in which said yieldable means comprises a plurality of circumferentially spaced resilient strands.

6. A device as in claim 5 wherein said resilient strands can be compressed to thereby urge said mounting members apart and wherein said device includes means for retaining said mounting members in said first positions.

7. A device as in claim 6 in which said retaining means releases in a predetermined period of time after insertion into the animals vagina to cause said yieldable means to elongate and collapse to thereby spontaneously be expelled peristaltically from the animals vagina.

8. A device as in claim 7 in which said retaining means includes an element solely soluble in vaginal fluid. 

1. In a device for insertion into the vagina of an animal of the type having a vagina terminating at the posterior end in a normally closed vulva and at the anterior end of the cervix, said vagina being defined by a fold-containing vaginal wall with a defined annular sphincter muscle intermediate the cervix and the vulva, said device comprising mounting means with an annular surface and spaced-apart yieldable means carried by the mounting means and projecting axially of the annular surface and being disposed circumferentially about an axis generally coincident with the axis of the annular surface, said spaced-apart yieldable means being capable of being compressed to a size so that the device can be readily inserted through the vulva into the vagina, said device being of a length so that it can be disposed between the cervix and the sphincter muscle, said spaced-apart yieldable means serving to place pressure upon the vaginal wall to distend the same from its normal cross-sectional configuration, said spaced-apart yieldable means defining a plurality of spaced channels adapted to permit vaginal fluids to bypass the same, said device being adapted to be completely disposed within the vagina to permit the vulva to assume its normally closed position.
 2. A device as in claim 1 in which said spaced-apart yieldable means are movable between collapsed and expanded positions, said yieldable means in a collapsed position being readily insertable into the animal''s vagina and in an expanded position engaging the vaginal wall.
 3. A device as in claim 1 in which said yieldable means is deformable at the ambient temperature of the animal''s vagina to partially collapse after insertion of the device.
 4. A device as in claim 1 together with a body and in which said mounting means comprises two separate mountIng members carried by the body and engaging said yieldable means at points spaced longitudinally of the body and assuming first positions.
 5. A device as in claim 1 in which said yieldable means comprises a plurality of circumferentially spaced resilient strands.
 6. A device as in claim 5 wherein said resilient strands can be compressed to thereby urge said mounting members apart and wherein said device includes means for retaining said mounting members in said first positions.
 7. A device as in claim 6 in which said retaining means releases in a predetermined period of time after insertion into the animal''s vagina to cause said yieldable means to elongate and collapse to thereby spontaneously be expelled peristaltically from the animal''s vagina.
 8. A device as in claim 7 in which said retaining means includes an element solely soluble in vaginal fluid.
 9. A device as in claim 1 adapted for insertion into the vagina of an animal having a cervix with a lip projecting into the same, wherein said device includes clamping means comprising a clamping ring adapted to be slid into engagement with the outer periphery of the lip and flexible linking means interconnecting said clamping means and said mounting means.
 10. A device as in claim 9 in which said linking means is formed of a plurality of flexible resilient strands capable of accommodating relative movement between said clamping ring and said mounting means.
 11. In a method for retaining a device over an extended period of time in the vagina of an animal of the type having a vagina terminating at the posterior end in a normally closed vulva and at the anterior end at the cervix, said vagina having an annular sphincter muscle intermediate said anterior and posterior ends, utilizing a device including mounting means and outwardly projecting radial spaced-apart yieldable means carried by said mounting means, said device being disposed between the animal''s cervix and vulva and said yieldable means being disposed between the animal''s cervix and sphincter muscle, the method comprising the steps of inserting the device through the animal''s vulva into the animal''s vagina into a position with said yieldable means disposed between the cervix and said sphincter muscle, permitting said yieldable means to engage the vaginal wall to expand the same to retain the device within the vagina while permitting the vulva to assume its normally closed position and permitting the device to remain in the vagina of the animal for a prolonged period of time.
 12. A method as in claim 11 in which said spaced-apart yieldable means are formed to assume a composite umbrella-like configuration and after insertion of the device into the vagina the outer periphery of the umbrella body engages the vaginal wall to the anterior side of the vaginal sphincter muscle for firm retention of the device.
 13. A method as in claim 11 in which the pressure applied to the vaginal wall is insufficient to cause extensive cutting of the vaginal wall or pressure necrosis of the engaged vaginal wall.
 14. A method as in claim 11 including the step of permitting reproductive tract fluids to flow past the area of contact of the device in the vaginal wall to minimize fluid contact and the growth of microorganisms.
 15. A method as in claim 11 in which the animal is of the type with a cervix having a lip which projects into the vagina and the device includes a cervical ring which slides over said lip to assist retention of said device in the vagina.
 16. A method as in claim 11 including the step of retaining the device within the animal''s vagina for at least one day.
 17. In a device for use in the reproductive tract of an animal in which the reproductive tract is characterized in that it is defined by a fold-containing wall forming an elongate sheath-like tubular passage with its anterior end leading from the cervix of the uterus and with its posterior end terminating in a normally closed vulva and which has an annular sphincter muScle between the anterior and posterior ends, said device comprising mounting means, said mounting means including an annular surface and spaced-apart yieldable means carried by said mounting means and being disposed circumferentially about an axis generally coincident with the axis of the annular surface, said yieldable means being deformable from a normal outwardly extending condition into a compressed condition, said device when said spaced-apart yieldable means is compressed being of a size so that it is completely insertable into the reproductive tract of the animal, said device being adapted to be located so that substantially all of the device is disposed between the cervix and the sphincter muscle, said device being capable of expanding within the passage into engagement with the fold-containing wall to expand the fold-containing wall from its normal state so as to inhibit the expulsion of the device by the animal, said device when in place in the reproductive tract being adapted to permit the vulva to remain in its normally closed position, said device being formed to permit fluid to pass from said cervix to said vulva. 